SINGAPORE - The Singapore Exchange (SGX) has made a formal offer to buy London's Baltic Exchange for £77.6 million (S$137.6 million).

Baltic Exchange shareholders will have to approve the acquisition offer of £160.41 in cash per share, the SGX said in an exchange filing on Thursday.

Baltic Exchange shareholders will also receive at least £18.80 in cash as a final dividend per share, subject to approval by Baltic shareholders and conditional upon SGX's offer becoming effective.

SGX reiterated in its exchange filing that " there is no assurance that the exclusivity agreement...will lead to any definitive agreement or completion of the potential transaction".

Its bid for the Baltic Exchange, a British institution that dates back to 1744, comes as the bourse works to grow products adjacent to its successful iron ore contracts.

The privately-owned Baltic Exchange is known for compiling the Baltic Dry Index, a prominent benchmark that tracks the cost of transporting commodities such as iron ore, coal and grain globally and is often used as a proxy for the global commodity trade.

The Baltic Exchange said it will consult with major shareholders to seek their support for the offer.

Subject to receiving sufficient shareholder support and endoresement from the Baltic board, a scheme of arrangement will be circulated to shareholders and a general meeting will be announced for shareholders to vote on the offer from SGX, the Baltic said in a statement.

A Baltic spokesman said the meeting was unlikely to take place before September, according to a Reuters report.